Camshafts

[bigcatchdaniel555]

i have read a few other post about camshaft selection and even then after reading the classic inlines i am still confused. i read in another post that a cam such as this...

Product ID: CSC-264-HDP-12
CSC-264/274 (112*) Hydraulic Dual Pattern Camshaft

would be good for a stock 200 with a 2bbl adaptor on a stock head. my question is, is this really a good cam for a stock 200 with a c4 and 2bbl. also what are the advantages of a bigger cam besides a lobby idle will this cam give more power/ fuel economy in everyday traffic and driving will it still idle reasonably smooth and not stall? also will it work with stock valve train and bottom end. dont mean to sound underinformed but the only cam swaps i have done are with new stock ones.

 

[AzCoupe]

The 264/274-112 cam will work great for you. Its by far the most popular cam we sell. You'll notice a marked improvement over the stock cam, but will still have a nice smooth idle (with a little lump) and good gas mileage. A lot of forum members are running this profile, so maybe some will chime in with their comments.

You can run a bigger cam, like the 274/274-112, but don't do it just to get a lumpy idle. If you have any vacuum assit periferals (power brakes or steering), you have less manifold vaccum and they won't work quite as well. You'll also need to bump the compression ratio, which means milling the head and/or changing to a thinner head gasket to compensate for the additional duration. However you'll have better throttle response with the increased C/R. In most cases, you'll lose a little bottom end power, but will gain some on the mid and upper rpm ranges with a bigger cam.

 

[bigcatchdaniel555]

thanks mike
i think that is probably the best cam too im not looking to scare the neighbors just a little idle would be nice and i dont want to lose too much economy or power.

 

[bigcatchdaniel555]

forgot one thing i dont think i have to change any of the valve train but do i?

 

[wsa111]

If you increase the compression ratio to at least 9.5+ and run 93 octane fuel and curve the distributor for more initial advance for a 36-38 degree total you will probably gain low end torque than the weak stock cam.

I run a 274 camshaft 4 degrees advanced with 10.2 compression & run 16 degrees initial advance with 20 degrees centrifigul in the distributor for a total of 36 degrees & i have much more torque than came stock.

If you have the proper combination you will gain & not lose, Bill

 

[bigcatchdaniel555]

i just saw this from comp cams any thoughts i'm a little scared of the 260 duration and 110 lobe for a basically stock motor. does anyone think it'll be too much it says best performance 1000-5000rpm so it looks like a good powerband but like i'm said i'm kinda in the dark on this one i dont want to do any headwork at this point just some new lifters and swap in a cam the nice thing about this one is it comes pre degreed.

 

[addo]

To install the lifters, you'll need to pull the head.

A rebuilder should be able to skim cut that head for you for $60 or less, to achieve your desired compression (measure everything when apart beforehand, and use the 10 thou cut per 2CC removed, rule).

The other good reason to factor in a little expense is frequently your exhaust gasket faces are eroded and need a skim or linish, too.

I wouldn't trust a cam to be "pre degreed". It may be super-close, it may be 11° off your specific application. Nor would I run the stock distributor gear with that cam. This is personal mistrust, no reflection on Mike's products...

A shopping list as I see it would be:
• Cam change gasket set
• Multi-keyway double roller timing set
• Cam and lifters
• Head skim
• Exhaust reface
• Uprated single valve springs
• Aftermarket hardened distributor gear

That may be more than you imagined, but being prepared for all that and pacing your work/parts orders accordingly means you won't be let down in the middle of it.

Personal opinion (again) says that cam will be right on the margin with a standard converter in the C4. It should work, but like medical procedures, you need to be aware that it may not be 100% of the intended outcome. Could be that you need to slip into N for some hilly stop-starts in traffic.

Regards, Adam.

 

[wsa111]

If you want to run the comp cams 260, you can use stock springs, because the cam is very mild & has a slow rate of lift.

If you want to install a real cam use Mike's 264-264 or the 264-274 & advance it 4 degrees. you will need stronger valve springs to prevent valve float cause of the faster rate of lift.

If you have a C-4 trans use the 112 lobe center with a stock converter, if its a stick shift go with the 110 lobe center.

As you can see i know the comp 260 camshaft is just a little more than a stock cam & a very weak performer.

If you want to use the stock valve springs & don't mind loosing 20-25 HP use the comp cam. My opinion from past experience.

 

[bigcatchdaniel555]

i was think of pulling the head anyway soon because i wanted to have it milled to ensure a flat surface for later upgrades so let me just get something straight so i'm doing the thing half baked. i want to use a generally mild cam to get a little more hp while still mantaining fuel economy with a little lump so a 264 with a 112 lobe is a good choice from Mike. then as far as the head goes it's stock now with 9.1:1 cr does it need to be more also i run 89 on it now it wont take 87 no matter what timing is carb setting etc. i looked at mikes site for spring and the ones i found were for a 289/ 302 would these be sufficient.
ps:i wanna keep the cr as low as possible to ensure runability on premium what i usually run now.

 

[bigcatchdaniel555]

forgot to ask sorry for the neglagence but where can i find a hardened gear for the dizzy the one i have on omy duraspark is the stock one i checked summitt and they have only the 240-300 listed.

 

[AzCoupe]

I've got hardened gears in stock, just never think to add them to the website. I'l do it over the weekend, as I need to add a few other parts too.

 

[wsa111]

Mike, yes you need to add the hardened distributor gears as well as the non oiling pushrods for using the oil through lifters so guys can use the 1.5, 1.6 rocker arms with the V-8 lifters & then if they want to go to the 1.65 yella-terra full roller arms later the lifters are already compatible with the camshaft.

This way if someone builds an engine & can not afford the 1.65 full rollers at that time, they have the option later on to step up to the best of the best that being the 1.65 yella-terra rockers which require an oil through lifter as well as the oil through pushrods which come with the 1.65 full roller rockers.

If you need the #'s from clay smith, PM me.

 

[michael_cini]

Interesting topic. Just the stuff I need to know.

Question: what dictates the quality of idle (lump)? Increased duration, higher compression, or lobe center? Or maybe it's all of them?! Can someone please explain.

Thanks.

Michael

 

[wsa111]

Question: what dictates the quality of idle (lump)? Increased duration, higher compression, or lobe center? Or maybe it's all of them?! Can someone please explain.

Michael, the lobe center & duration both contribute to a rough idle.
Even valve diameter if larger will roughen the idle.

The larger engine you have 250"-200" the 250 will absorb more duration & smaller lobe center than a smaller engine. Another X factor is your transmission if a C-4 & you have a stock stall converter or a custom high stall converter, or do you have a stick shift.

Each combination requires a different match of the proper componets.

Even rear end ratio is added into the equation when a higher than stock stall converter is added with a camshaft with a closer lobe center & or more duration.

More confused now, you need to read Mike's articles on camshafts www.classicinclines.com He does a good job to help you on camshaft specs.

Contact phoenix trans in dallas for any C-4 converter questions.

http://www.phoenixtransmissionproducts.com/

Hope this helps rather than confuse you, bill

 

[michael_cini]

Thanks for all of the information Bill. I have read the article on the classic inlines site (several times). I guess one of the problems is that I have been getting different opinions from different people. Such as: you had suggested that I should use the 112 lobe center with my C4 tranny. You mentioned that in your car it had a nice lump, but the classic inlines pages says it has a smooth idle and that the 110 would have a lopey idle. My machinist seems to think a 110 or 109 would be good. I think I will put the OZ cylinder head on the car with new lifters and see how it performs. Perhaps that will give me some indication on what cam to proceed with.

Thanks again. I will sort it all out...eventually!

Question: what dictates the quality of idle (lump)? Increased duration, higher compression, or lobe center? Or maybe it's all of them?! Can someone please explain.

Michael, the lobe center & duration both contribute to a rough idle.
Even valve diameter if larger will roughen the idle.

The larger engine you have 250"-200" the 250 will absorb more duration & smaller lobe center than a smaller engine. Another X factor is your transmission if a C-4 & you have a stock stall converter or a custom high stall converter, or do you have a stick shift.

Each combination requires a different match of the proper components.

Even rear end ratio is added into the equation when a higher than stock stall converter is added with a camshaft with a closer lobe center & or more duration.

More confused now, you need to read Mike's articles on camshafts www.classicinclines.com He does a good job to help you on camshaft specs.

Contact phoenix trans in dallas for any C-4 converter questions.

http://www.phoenixtransmissionproducts.com/

Hope this helps rather than confuse you, bill

 

[AzCoupe]

I think your confussion is in the definition of smooth or lopey, and/or rough.

To me the wav file below has a idle somewhere between smooth and lopey. I would not classify it as lopey, however you can definitely hear the cam. Lopey does not mean rough either, at least IMO. Lopey is the gray area between smooth and rough. If that makes any sense. Basically, three words are not enough to describe the entire range of a cam profile. They need more like six. Smooth, smooth lope, lopey, rough lope, rough, and extremely rough.

http://www.classicinlines.com/videos/falcidle.wav

You should not purchase a cam based on sound, if that's what you are doing. Big mistake. You need to match the cam to your specific build, the vehicle, and your driving requirements. The basic rule of thumb is 112 for an automatic, and 110-108 for manual, but it's not "set in stone". Your mechanic has given you his recomendation based on everything he knows about your build. Stop worring about it so much and put in the cam that's best suited to your combination, based on his recomendation.

Here's a couple quotes that make a lot of sense.

Honestly access what your intended use is before starting any performance upgrades. If you intend to use the car as a daily commuter, you probably do not want a 330 degree mechanical cam, a 12.5:1 Compression Ratio, and 5.30 rear gears! And you certainly don't want to build an engine that is a real screamer at 7000 rpm if it's going to be used in a rock-climbing Bronco or street driven in stop and go traffic!

The rest of the drivetrain should be matched to the powerplant. Even a properly built high-performance 200/250 may be no fun to drive if torque converters and gearing are not matched to the engine's capabilities. 2.79 gears can be a bummer if you build an engine that makes 240hp at 6500 rpm but only 30 hp at 1500 rpm!

So, which cam do you use? A car that idles rough, stalls in gear, is a bear to drive in traffic and gets poor gas mileage is still cool if it rocks when you floor the gas pedal. An engine that suffers these driveability headaches and still gets blown away by a Ricer is the worst possible experience. The most prevalent reason for engines that don't run as they should is an improper camshaft for the engine and vehicle combination.

We'd all like to have a 10-second car with a great stereo, air conditioning, 30-mpg fuel economy and 1.2g handling capability, but reality says that isn't going to happen unless your surname is "Superman". In the real world a street car is built for either ultimate straight-line quickness, driveability with some performance, or a combination of both, which ultimately means a compromise of both. Do you want the car to run low ETs or get you to work every day? Does the car have an automatic or manual transmission? How rough an idle can you put up with?

Everything about the car combination and intended function must be decided upon before choosing the cam. Once this is determined, the following important details must be taken into account to get exactly the right camshaft: the engine's compression ratio, the basic power range of the heads, intake-manifold-carb and header combination, the car's weight, the transmission type (and/or torque converter stall speed), the rear gear ratio and the rear tire size. Once you've decided how you want the car to behave, you must build the entire engine and drivetrain to fit.

 

[michael_cini]

Hi Mike,

Thanks for that. Which engine/cam is that, it sounds nice. Do you have any other wav files to hear the difference with more or less lope?

Michael

I think your confussion is in the definition of smooth or lopey, and/or rough.

To me the wav file below has a smooth idle, and I would not classify it as lopey. However you can definitely hear the cam. Lopey does not mean rough either, at least IMO, its just somewhere inbetween smooth and rough. If that makes any sense.

http://www.classicinlines.com/videos/falcidle.wav

 

[michael_cini]

Hey! I just noticed that you edited/updated your previous response Mike. Thanks!